Monday, March 19, 2012

Anterior vs. Posterior tuck in Classical Tai Chi

                      Tai Chi demonstration Buffalo, NY 2006 to benefit Literacy Volunteers of WNY

First of all, this is not an argument with anyone as to which is “better”, more “powerful” or a tribute to “our style does it this way and thus it is the correct way”.  Whether Karate, Kung Fu, Boxing, MMA, etc., is not the issue here;  I don’t care to argue with students with experience from other styles or no.   I recall a student who quit after 8 years of study in Wu style Tai Chi when he said:  “You are studying Classical Tai Chi and I don’t understand why.  I can see where Wu Style gets its power but for the life of me, I cannot see where Classical Tai Chi gets its power”.  As my teacher, Master Stephen Hwa says, “They  do not do “internal” Jim, so how should they understand”.

Which brings me to my next point and that is how Classical Tai Chi gets its power. For that we have to do a bit of an analysis on how Classical Tai Chi utilizes the body to derive internal motion but by means of comparison and an understanding that internal energy comes from places in the body that most do not even know exist.   In external styles , the power comes from a tremendous push and surge from the back leg, driving the punch forward.  I will not do further analysis on how external styles “use the hip”, suffice it to say, that the back leg acts to push and drive forward.  What is obvious in external stylists, or even beginning Tai Chi students with no experience however,  is how their spine and lower back is tilted. 

Most of the students I have taught in Classical Tai Chi, come to the discipline holding the hips in a position where the buttocks are in an anterior tilt.  What is an “anterior” tilt? When I ask them to stand with their back to a wall they readily see that the small of the back is normally an accentuated curve, an anterior tilt.  It is of course unintentional that the hips are positioned in this manner but for the most part I believe that it is related to the lifelong habit of using the legs to push the body forward and back…in other words what we call normal walking.  In moving forward for instance, the back leg pushes, the front leg reaches or some would say “swings” forward, the accompanying hip also “swings” forward and the back leg straightens.  When the back leg straightens, the hips will tilt back by default.  At the same time I studied Tae Kwon Do and Isshin Ryu Karate,  I was also studying Tai Chi and I could notice such a contrast where the deeper my stance even when I was motionless, the more my hips seemed to tilt.

Not with the “Taoist” Style, Yang Style or even Wu’s Style, but it was finally with my own personal study of Classical Tai Chi that I found how incredibly important it was for the hips to be tilted forward which is called “tucking” the pelvis or a “posterior” tilt.  In the world of Tai Chi “stances”, or “frames” (the size of things), Classical Tai Chi is incredibly compact but is the poster child for the cliché’ that good things come in small packages. The tailbone is pulled under and down in a process where the spine is stretched both downward and upward if the rules about “stretching the head” up are followed correctly.  When I have my students stand with their back to a wall, they readily see  and perhaps for the first time, that the small of the back can be straightened.

To add to the problem of taking “command and control” of a tilted back pelvis (anterior tilt) in Classical Tai Chi a beginner will find that it is also  quite a distance from their pelvis to their shoulders.  As a former Tae Kwon Do and Karate practitioner I had the disconcerting and sometimes painful experience as a beginner of hitting the enormous heavy bag while it was swinging toward me and finding that my shoulder gave way.  I of course managed to learn to correct this problem but it is only later in my advanced Tai Chi studies that I now understand this as a corresponding “giving way” or “disconnect” in my body structure.  As a beginner in Tae Kwon Do I was amazed as a beginner, at how little power I had when punching the bag.
Where exactly does the power or ability to deliver force go when the hips are tucked under and when they are not?  For one thing I have come to realize that the road to connecting the torso or “core” of the body to the legs, as my teacher says,  goes directly through the pelvis and hips.  In any fashion I can do this by tightening my abdominal muscles but what happens when I stretch my abdominal muscles?  In the “anterior” tilt of beginners that I  described ?  Well, this “stretching”(energizing) and not “tightening” (tensing) of the abdominal muscles is exactly what happens when the hips are back and not tucked.

Then we come face to face with Newtonian physics as well because we find our high school science teacher was right when he drilled “every action has an equal and opposite reaction” into us.  Hitting that heavy bag with a punch “action” can only be accomplished if your force is less than the amount of “reaction” support.  If the body muscles achieve a great amount of muscular energizing (there are many who abhor the word tension so we use energize)  when the fist hits the bag, then the greater the power in the punch.  I should point out at this juncture however, that  the “internal” style of Classical Tai Chi achieves such “great muscular energizing” in a manner far different than “external” styles as I explain forthwith.

There is another problem with the body’s ability to withstand reaction force and that has to do with how much strain its structure can withstand in delivering the punch.  It is true that in an external punch the back leg “drives” forward but that drive is mostly in a horizontal fashion.  All of us humans align our body vertically however.  The horizontal “drive” line of force from the back leg intersects the body at the point where it becomes vertical.  The result is an increase of pressure at the hips and pelvis…where the hips are either tucked or not tucked.

One only has to think of a basic analysis of the physics involved in why  sprinter’s start all races in such a crouched position.  It is also easy to see that sprinter’s keep the hip very “tucked” and in fact very well “tucked” in the starting position. In that crouched position, with hips tucked,  the push from the back leg will also support a great amount of reaction force and as we know a great acceleration can be achieved.  It is interesting however that videos of sprinters taken while they are walking show they have almost severe “anterior” pelvic tilts and buttocks that protrude quite a bit.  Humorously, these folks do not need belts to hold their pants up. 

Classical Tai Chi is where it all comes together because the action at the hips and pelvis is dynamic.  That is to say that the body will fluctuate appropriately between “anterior” and “posterior” tilts of the hips. The back leg is also not acting to powerfully “push off” like a sprinter.  In fact, whether moving forward or back the lead leg (after all depending on your viewing angle, a “back” leg can be in either front or back) is pulling and not pushing.  Quite frankly, the step size and vertical structure of Classical Tai Chi will not accommodate a powerful “push off” from the leg, it would topple your body.  So the extreme "energizing" necessary to drive a punch has to come from skillful movements of  the core and not the back leg.  In Classical Tai Chi we call such movements “quarter body movement” and as an example, one “quarter” of the core itself is actually fully engaged with the arm.   The “quarter” of the body achieves extreme energizing and then it relaxes instantaneously after the power is delivered. In doing so we can accomplish the famed “one inch punch” so popularized by Bruce Lee…but we do not have to stand in the large stance that he adopted to do so.

Any muscular energizing from the core will use the back leg to act as a shock absorber to the reaction force from the punch. Not a perfectly straight back leg which had to work to drive the body forward either.  Here is why we see,  it is also not necessary for the aficionado of Classical Tai Chi to beat on a makiwara or heavy bag to “practice their punches”.  This in contrast to the protestations of a student who lamented to both Master Hwa and I that he had not developed “self defense abilities” in his Tai Chi practice.  He was going to study Wing Chun instead of Tai Chi and build a makiwara so that he could practice his “power” punches. In studying the small frame stance of Wing Chun stylists, it is relatively easy to see they also “tuck” their hips under.  The disillusioned student will be right back where he was in the first place.  He certainly will not achieve power if he punches the makiwara or heavy bag by holding back his hips in an “anterior” tilt from such an upright stance.  Every time he punches with that tilt a great pressure will be exerted against the spine in an unusual direction.  Does he also plan to straighten his back leg in such a small frame stance, thus compounding  the pressures on the spine and small of the back?  How will he stay “rooted” if he pushes off, or does he plan on his body leaving the ground with every punch?


DungHo said...

Hi sifu. This is Anh. I can attest that Wing Chun also tuck the hips under. The tucking is really important in Wing Chun because of the vertical structure. The lineage that I studied is soft and it really emphasizes tucking.

Anonymous said...

Hi Jim,

What a great post and I like the new blog look by the way (new to me anyway). I read the post with great interest and I can relate to your bio-mechanical analysis of the 'tuck'. Since November last year I had purposefully ceased with my learning progression of the square and round forms and made a conscious decision to consolidate what I had learned. The reason for this was purely because I was going through a turbulent time in my life and didn't want to fudge my way through any new moves. By that I mean simply that I have trained daily but only practising up to where I'm at - namely the start of the Jade Lady sequence.

I have had plenty of opportunity to observe (and I've found this to be key to my learning - simply to observe) what my hips, lower back, pelvis et al are doing... or not doing in my case. I have found that my lower back is now a lot looser than 5 months ago, this in turn makes it easier to perform the tuck. I now find myself in a body/mind state whereby I am concious of whether my back is tight or not so tight. I still have a way to go before I am as 'loose' or pain free (?) as I would like but I have made significant improvement.

I began (as mentioned in your post) by standing with my back against a wall - on November 15th 2011 I was absolutely horrified to discover that not only did I have the hollow curve in my lower back but I could not straighten my upper back nor even rest the back of my head against the wall without forcing myself and causing pain! Well, after that initial shock I took a good look at myself and thought "Hang on a minute John - I'm only 43 years old, I'm not really ill, I have no diseases and all my limbs work okay as does my core...". I have had (and still have) lots of niggling aches and pains in various parts of my body - but nothing disabling. So I decided to look logically at my body and deduced that if everything works when I test it and I can do Tai Chi as well as many other things then the pain and tightness I have must be down to me somehow. This in turn brought me back full circle to the fact that maybe I am suffering with tension/stress/whatever. I then began to stand daily (hourly actually) against the wall and try to relax and flatten my back out. Kind of like standing qigong I suppose, starting with only seconds at a time and gradually extending to 15-20 mins. During this process I observed all kinds of things going on in my body (I even felt how tight my calf muscles were and how they are connected/influenced by the back) and trying to 'let go' has proved painful but worth the investment. Now I really do notice the difference when my lower back is tight (which has been 'normal' for me for so many years) and when it's not. Also performing the Tai Chi walk more deliberately and slowly with long pauses to observe has helped a great deal. I find that to relax the lower back I also need to let go of my lower belly as I seem to hold myself there quite a lot for some reason.

So, glad to be back and glad to report that I have made progress. Still a long way to go though. I suppose in a round about way here I'm just reiterating what people who know better have already advised! I hope this may help someone else.


Classical Tai Chi of Buffalo said...


You are right. One can make the statement in 2 ways: "There is a tightness in my back" or "I am making my back tight".


Classical Tai Chi of Buffalo said...


We do not have such horizontal force coming at us in normal movement as we do in Tai Chi, Wing Chun, etc. It is interesting that I hear no talk of how the core in both Wing Chun and Tai Chi works to reduce such horizontal force. The common statement I hear is how there is such compression forces at work which stress the spine in a tucked position. Nothing is ever said about the role of the core in reducing that force.